How Distributed Energy Sources Affect Technical Requirements to Relay Protection and Automation

The last decade has seen increased interest of Russian manufacturers in distributed generation (DG), as it can produce cheaper energy for less costly and more competitive manufacturing. In some cases, critical users that cannot afford power outages have to construct hydrocarbon-fired DG facilities. This paper analyzes the electric parameters of power districts that contain distributed energy sources (DES) and how those parameters change in a variety of operating situations. It has been found that fast electromechanical transients might cause the power quality to vary significantly, and short-term fluctuations in the parameters to occur in a wide dynamic range, especially in case of islanding. The paper considers the core factors that necessitate changes in the requirements to relay protection and automation systems (RPA) shall DES's be integrated in distribution grids on a large scale. The authors here of present their guidelines on how to tackle various issues when projecting the development of, or operating distribution grids.